The present invention relates to a printer and, more particularly, to a printer having a multiple font control function, which is designed to improve a method of supplying character pattern development programs inherent in the respective fonts.
As shown in FIG. 4, a conventional printer of this type has a printer main body 15 comprising a master control section 1 constituted by a CPU, a program memory (program ROM) 2, a buffer memory 3 (buffer RAM) 3, a B type font data memory (print ROM) 4, a print control section 5, a cartridge loading section 6, and a printing mechanical section 13. In addition, a cartridge 17 incorporating an A type font data memory 8 is detachably loaded into the cartridge loading section 6, as needed, to be operated under the control of the master control section 1. In such control of a plurality of fonts, development programs respectively corresponding to all the fonts are stored in the program memory 2 incorporated in the printer, provided that each program for developing font data into character patterns is defined as an inherent program by the data format of a font. If newly formed font data requires a complicated development program, the program memory 2 in the printer main body 15 is replaced with a corresponding memory.
In this conventional printer, however, if one of a plurality of cartridges respectively incorporating memories for storing a plurality of fonts having different data formats is to be supplied to the printer main body, since all the programs for developing font data into character patterns are stored as part of a microprogram in the printer main body, the memory space managed by the internal storage elements and the microprocessor is greatly increased in size. Consequently, the space used as a buffer and the space for storing programs associated with an extended control function are undesirably limited. In addition, when a new font is formed, and a printing operation is to be performed by the printer according to the font, the data format of the font must conform to one of the development programs stored beforehand in the printer main body. This makes it difficult to form font data.